My Lyne Up undershirt arrived beautifully packaged with the full instructions on how to use it. To be fair, it’s pretty straight forward but it’s nice to know that you are wearing it correctly. So I immediately noticed the undershirt was making me stand taller and sit better. It sort of pulls your body into the posture you should have when you are sitting or standing. It was very comfortable to wear and felt like it was making a difference immediately. The undershirt is made of thin material, so it can easily be worn under another vest top or t-shirt. Ideal as you wouldn’t want anything too hot – as you would just give up wearing it. I’ve worn my Lyne Up undershirt for a few hours each day. I’ve worn it when I’ve been at home as I would feel a bit silly with the bottom straps undone, but if I could wear them done up, I would happily wear it out. I’ve mainly worn it when I’ve been working at my desk, pottering around the house and playing with my son on the floor. It definitely helps me maintain a better posture and I’ve noticed a significant reduction in my backache since wearing it. Obviously, I’m not a medical professional so I cannot tell you that my decrease in backache has been down to Lyne Up, but they have done some clinical studies, so it would be worth you checking these out.